中文摘要：

电力机车通过分区段时，应用地面自动过分相技术，实现供电电源的自动切换，电力机车变压器要进行断电和上电操作，由于电力机车变压器是带负载开断，断电后的变压器存在残压．残压与待投入相的系统电压的频率、相位、幅值都可能不同，加上变压器剩磁的作用，在上电瞬间可能会产生很大的涌流．本文分析了电力机车变压器在投入时系统的暂态响应．通过仿真，针对不同的系统电压相位，确定电力机车变压器投入的最佳时刻，经实验验证，选择合适的系统电压相位角投入机车变压器，能达到减小涌流，减小对系统造成的冲击．

英文摘要：

Auto-passing phase division on the ground switch automatically appnes me power supply tu the electric locomotive which is passing by the neutral section. During this process, the transformer on board is switched off and switched on in sequence. Residual voltage appears on the transformer since the transformer is switched off with load. The frequency, phase and amplitude of the voltage to be supplied may differ from those of the residual voltage, thus the difference and the residual magnetism of the transformer result in large inrush current when the transformer is switched on. This paper ana- lyzes the transient response of the transformer when power is supplied. Through simulation, it is de- termined the optimal moment when the transformer is switched on, according to the system voltage phase. Test is carried on to verify the performance of optimal switch scheme. The results show that it effectively reduces the inrush current arid the impact on system.